CN111693790A - Annular distance-reducing antenna testing device - Google Patents

Abstract

An annular reduced-pitch antenna testing device comprises a group of annular main reflecting surfaces, a single group or a plurality of groups of auxiliary reflecting surfaces and a single group or a plurality of groups of signal feeders. The main reflecting surface is an annular reflecting surface, and the main reflecting surface is sunken to the annular central axis. The geometrical shape of the secondary reflection surface is obtained based on the wave characteristic principle of the Fermat principle. If a plurality of sets of plane waves are generated and directed toward the central axis of the ring from different directions, the geometrical shapes of the corresponding sets of auxiliary reflection surfaces can be calculated by using different blocks on the ring reflection surface and corresponding positions of different signal feeders. The invention can generate a plurality of groups of incident plane waves in different directions in an antenna test quiet zone, simultaneously provide the measurement of the radiation field patterns of the antennas of one or more groups of antennas in different directions, and can rapidly measure the radiation field patterns of two-dimensional and three-dimensional antennas.

Description

Circular Reduced Pitch Antenna Test Set

technical field

The invention relates to a device for generating multiple sets of incident plane waves in different directions into the test quiet zone through a ring-shaped reflecting surface, combining different sets of auxiliary reflecting surfaces and multiple sets of signal feeders, for antennas at different positions to measure the antenna field at the same time type (Radiation pattern) of the device.

Background technique

At present, when measuring the radiation pattern of an antenna, the antenna needs to be placed in a region that can receive a similar ideal incident plane wave. , the area where the electric field phase of the wavefront is the same size, the area under this condition is called the Quiet zone. In order to achieve an ideal plane wave, the distance between the antenna to be tested and the emission source must be infinite, and there should be no multiple reflections, refraction, or diffraction during the propagation of the radio wave. Therefore, the plane wave depends on the specification requirements. The electric field amplitude (Amplitude) of the wavefront (Wavefront) and the electric field phase (Phase) size of the wavefront can be slightly relaxed, such as the existing far-field anechoic chamber test quiet zone specifications on the market (such as the test quiet zone The magnitude is D, λ is the wavelength, and the measurement distance R is 2D ² /λ, the quadratic phase difference of the electric field of the wavefront is 22.5 degrees, plus the influence of multi-path reflection or diffraction of the radio wave), which is ±1 for the fluctuation of the electric field amplitude Decibel, electric field phase ripple (ripple) is ±6 degrees. If the wavelength is shorter (the frequency is higher), in order to maintain the same test quiet zone size D, the measurement distance R needs to be increased, and correspondingly, the space of the microwave anechoic chamber needs to be larger.

In order to have a large test quiet zone in a limited space, and the size of the test quiet zone is not affected by the frequency, the existing antenna field type measurement devices are mainly the compact antenna test range (CATR, Compact Antenna Test Range). ) device is implemented, and the existing telescopic antenna measurement devices can be mainly divided into two types, the telescopic antenna measurement field with a single reflector, and the telescopic antenna measurement field with double reflecting surfaces. The measurement field of the single-reflecting antenna with a reduced distance is made of an eccentric part of the paraboloid as the main reflecting surface. The feed source is placed at the focus of the paraboloid. Considering the better antenna power efficiency, the radiation measurement field test quiet zone of the telescopic antenna is small. For the radiation measurement field of the double-reflecting surface, the main reflector is an eccentric part of a paraboloid (Paraboloid) as the main reflector, and the geometry of the auxiliary reflector is a part of an ellipse (Ellipsoid) or a part of a hyperboloid (Hyperboloid). ), the inner (or outer) focal point (Focus) of the auxiliary reflecting surface overlaps with the focal point of the paraboloid, the feed source is placed at the outer (or inner) focal point of the auxiliary reflecting surface, and after the spherical wave radiated by the feed source is reflected by the auxiliary reflecting surface, it is The equivalent virtual feed is placed in the inner (or outer) focal point of the auxiliary reflection surface. The spherical wave is a plane wave after being reflected by the main reflection surface. For example, considering the same antenna power efficiency, the double reflection surface The formed test quiet zone is larger than that formed by a single reflective surface.

In order to make the amplitude of the electric field and the ripple of the electric field of the plane wave in the test field of the above-mentioned two types of telescopic antennas have little variation, in addition to the small distortion of the surface geometry of the reflective surface, the edge of the reflective surface needs to be specially treated , For the edge processing of the reflective surface, it is common to add multiple serrated edge reflective surfaces to the edge, or use the rolled edge type to the edge. The more reflective surface edge processing will increase the cost and the complexity. In addition, if multiple plane waves are required to enter the test quiet zone from different directions, for the test of multiple antenna radiation patterns at different positions and different directions on the vehicle to be tested in the quiet zone, multiple groups of reduced-distance antenna measurement fields are required. Since the main reflecting surface is a paraboloid, the installation complexity and space requirements are increased.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a method that, in addition to low complexity and space saving requirements, has multiple incident plane waves in different directions in the test quiet zone of the measurement field, which can be used by multiple antennas at different positions and different directions on the carrier. A test device for time measurement of various field types of ring-shaped reduced-distance antennas.

The test device of the annular telescopic antenna according to the present invention comprises a torus main reflection surface, at least one auxiliary reflection surface with the same geometric shape (or different) at different positions, and at least one signal feeder relative to the auxiliary reflection surface .

The main reflecting surface is an annular reflecting surface, and any point on the surface is composed of two main curvatures that are perpendicular to each other, one of which is the curvature of a first curve in the shape of a circle, and its curvature radius varies with the second curve The position of the center of curvature changes with different heights, but the center of curvature is always at the center of the quiet zone of the test field, and the center of curvature of another second curve is in the ring, and its shape can be parabola or hyperbola. , Ellipse, Circle, and any curve that can be represented by a formula.

The geometry of the auxiliary reflection surface is determined by the partial reflection area on the main reflection surface and the corresponding feed position. The spherical wave radiated from the feed position is reflected to the main reflection surface by the auxiliary reflection surface, and then reflected by the main reflection surface to become a plane wave, which is directed to the center of the test quiet zone. According to the Fermat principle, between the two waves in progress The phase difference of the relative positions is equal, and Snell's law, at the reflection point position, the incident angle is equal to the reflection angle, the incident direction, the reflection direction, and the normal of the reflection point position are coplanar. Therefore, the distance R from the feed source position to the reflection point on the auxiliary reflection surface, plus the distance L from the reflection point on the auxiliary reflection surface to the relative reflection point on the main reflection surface, plus the distance M from the main reflection surface to become a plane wave after reflection, Then according to R+L+M as a fixed constant and Snell's law, the geometry of the auxiliary reflector can be calculated.

Furthermore, another object of the present invention is to provide an incident plane wave with multiple incident plane waves in different directions in the test quiet zone of the measurement field in addition to low complexity and space saving requirements for different positions on the carrier and different Multiple antennas in multiple directions can measure different field types at the same time.

The test device of the annular reduced-distance antenna of the present invention comprises a main reflection surface, at least one signal feeder, and at least one auxiliary reflection surface.

The main reflecting surface is annular.

The at least one signal feeder is spaced apart from the annular main reflection surface.

The surface geometry of the at least one auxiliary reflecting surface is jointly defined by the surface formula of the main reflecting surface and the position of the signal feeder.

The three cooperate with each other to generate a plurality of plane waves incident in different directions in a test quiet zone, which is used for field measurement of multiple antennas receiving or transmitting.

Preferably, the annular main reflecting surface is composed of two orthogonal curves, the trajectory of one curve is a circular line, the center of which is on a central axis of the test quiet zone, and the trajectory of the other curve is a parabola, a double curve. One of a curve, an ellipse, a circle, and a curve that can be represented by a formula.

Preferably, the annular main reflection surface is composed of two curves, a first curve is a circular curve, and the center of the circle is on the central axis of the test quiet zone.

Preferably, another second curve of the annular main reflecting surface is a parabola formula.

Preferably, another second curve of the annular main reflecting surface is a hyperbolic formula.

Preferably, another second curve of the annular main reflection surface is an elliptic line formula.

Preferably, another second curve of the annular main reflecting surface is a curve that can be expressed by a formula.

The effect of the present invention lies in: the main reflection surface formed by the first curve around the central axis, and the defined radiation space, and the surface formula of the main reflection surface and the position of the signal feeder are jointly defined The auxiliary reflecting surface can generate electromagnetic waves for measurement traveling in various directions in the radiation space, and then can measure the corresponding electromagnetic radiation parameters received by the at least one antenna at a specific time point. The geometric structure of the reflective surface reduces the area that needs to be processed at the edge, and can increase the size of the test quiet zone, thereby reducing the construction difficulty and manufacturing cost of the reflective surface.

Description of drawings

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein:

1 is a top view of an embodiment of a ring-shaped telescopic antenna test device of the present invention, and a front view of generating a plane wave in a middle direction, illustrating a ring-shaped main reflector, a plurality of auxiliary reflectors, and a plurality of feed positions of the present invention the schematic diagram;

FIG. 2 is a schematic diagram to assist in illustrating the arrangement positions of the relevant components of this embodiment;

Fig. 3 is a partial schematic diagram (including the main reflection surface, the auxiliary reflection surface, the position of the feed source, and the test quiet zone, etc.), illustrating the arrangement position of the relevant components and the traveling direction of the electromagnetic wave in a radiation space of this embodiment; and

Figure 4 illustrates the simulated beamforming direction of the example. The multi-beams in the test quiet zone have plane waves in the directions of 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° respectively. The test of this example The variation range of the plane wave amplitude dimension of each beam in the quiet zone is ±0.65 dB.

Detailed ways

Referring to FIG. 1 and FIG. 2 , an embodiment of the Toroidal compact antenna test range of the present invention is used for measuring a plurality of antennas 21 in a test quiet zone R2 after receiving plane electromagnetic waves. Antenna radiation pattern parameters, including a torus main reflector 31, at least one feed horn 4, and at least one sub-reflector 51.

It should be noted that the number of the signal feeders 4 and the sub-reflection surfaces 51 in this embodiment can be multiple, and each signal feeder 4 is installed in a different position, and the geometric shape of each sub-reflection surface 51 can be The same or different, the number of the signal feeder 4 and the auxiliary reflection surface 51 in the following description of this embodiment is all plural.

Any point on the annular main reflecting surface 31 is composed of a first curve C1 that is a circular curve, and a second curve C2 that is orthogonal to the first curve C1. The shape of the second curve C2 is a circle A curved curve, parabolic curve, elliptic curve, hyperbola, and any curve that can be represented by a formula, a radius of curvature L1 of the first curve C1 changes with the height position of the second curve C2, but the center of curvature of the first curve C1 is always at Test on the central axis L2 of the quiet zone. Therefore, the main reflection surface formed by the first curve C1 and the second curve C2 is a ring-shaped main reflection surface.

It is further explained that the substantial appearance of the main reflection surface 31 is surrounded by a ring, and the surface is arc-shaped, and the space surrounded by the main reflection surface 31 in a ring form is the defined radiation space R1, and the first The trajectory of the two curves C2 satisfies the parabola formula, the ellipse line formula, the hyperbola formula, the circle formula, or the curve that can be represented by the formula, etc. In the actual design and manufacture of the main reflecting surface 31, due to the symmetry of the shell on the first curve C1 and continuity, there is no edge diffraction problem, and the amplitude of the electric field at the edge of the second curve C2 can be determined by the field type of the signal feeder and the auxiliary reflection surface, so the edge diffraction processing is relatively simple, so that in addition to simple construction, the The main reflector 31 will also have a larger test quiet zone size. More specifically, any point on the surface of the main reflective surface is composed of two main curves that are perpendicular to each other, one of which is a circular line (Circle), the center of which is located on the center of the axis of the test quiet zone, and the other is a circular line. The orthogonal curve can be a parabola, a hyperbola, an ellipse, a circle, and any curve that can be represented by a formula.

In addition, the antenna 21 to be measured is placed in a test quiet zone (Quiet zone) R2 of the radiation space R1, the test quiet zone R2, in this case, the amplitude change of the plane electromagnetic wave in this zone is 1.3dB, that is, the amplitude ripple is between -0.65dB and 0.65dB, and the phase angle ripple is between -5° and 5°.

The signal feeder 4 is located in the radiation space R1 and radiates a plurality of feed signals related to the plane wave, wherein S1 to S3 are each effective radiation area of the feed signal radiated by each signal feeder 4 .

The surface formula of the auxiliary reflection surface 51 is jointly defined by the surface formula of the main reflection surface 31 and the position of the signal feeder 4 , and the signal feeder 4 enters the feed into the auxiliary reflection surface 51 . When a spherical wave signal is generated, the auxiliary reflecting surface 51 reflects the incoming spherical wave signal to the main reflecting surface 31, and then reflects the plane electromagnetic wave traveling in the traveling direction toward the central axis L2 through the main reflecting surface 31, which is used to supply the load. The measured antenna 21 generates corresponding field parameters after receiving, and the receiving analyzer 22 measures the relevant data.

It should be noted that the surface geometry of the auxiliary reflection surface 51 is determined by the surface formula of the main reflection surface 31 and the position of the signal feeder 4 in combination with a geometric ray tracing method.

In addition, the present invention can also use a ring-shaped main reflector to cooperate with the same (or different) auxiliary reflector and feeder to achieve plane waves in different directions in the test quiet zone.

Furthermore, the present invention can also use a ring-shaped main reflection surface to cooperate with a feeder that mechanically moves along a fixed track and its corresponding auxiliary reflection surface to achieve plane waves with opposite directions in the test quiet zone, and to support the second antenna to be tested. The three-dimensional rotating table can simultaneously test the three-dimensional radiation pattern of the antenna of the multi-antenna system.

As mentioned above, the embodiments of the present invention can not only rapidly test the two-dimensional (Twodimension) pattern of the antenna of the multi-antenna system, but also can quickly test the three-dimensional antenna of the multi-antenna system if a turntable is added to support the antenna to be tested. (Three dimension) field type.

Referring to FIG. 4 , in the actual simulation of this embodiment, for beamforming in different directions (45°, 90°, 135°, 180°, 215°, 270°, 315°, 360°) toward L2, From the results, it can be seen that in this embodiment, plane incident waves can indeed be formed in all directions of L2 and received by the antenna under test.

To sum up, the ring-shaped reduced-pitch antenna test device of the present invention reduces the area that needs to be edge-treated through the geometric structure characteristics of the main reflector with the ring-shaped appearance, thereby increasing the size of the test quiet zone, thereby reducing the difficulty and difficulty of construction of the reflector. manufacturing cost. Therefore, the creative purpose of the present invention is indeed achieved. On the other hand, since the first curve trajectory of the main reflecting surface is a circular formula, the annular orthogonal second curve trajectory can be a parabola formula, an ellipse line formula, a hyperbola formula, a circle formula, or a curve that can be represented by a formula etc., the geometry of the auxiliary reflection surface is determined by the partial area of the main reflection surface and the position of the signal feeder. For example, if the positions of multiple signal feeders are arranged in a circle, the relative positions of the annular main reflection surface define a The geometry of the opposite auxiliary reflector will have plane waves incident in different directions on the central axis of the test quiet zone. Furthermore, according to the simulation results obtained with actual parameters, it is fully verified that the multi-antenna is used in the measurement of the telescopic antenna of the present invention. Each of the devices can simultaneously receive plane electromagnetic waves from different directions for one or more antennas to simultaneously measure the radiation pattern of the two-dimensional antenna.

The above are only preferred embodiments of the present invention, and should not limit the scope of the present invention, that is, any simple equivalent changes and modifications made according to the claims and description of the present invention are still belong to the scope of the present invention.

Claims (7)

1. a ring-shaped reduced-distance antenna test device, is characterized in that, comprises: an annular main reflector; at least one signal feeder, arranged spaced apart from the main reflection surface of the ring; and at least one auxiliary reflection surface, the surface geometry of which is defined by the surface formula of the main reflection surface and the position of the signal feeder, The three cooperate with each other to generate a plurality of plane waves incident in different directions in a test quiet zone, which is used for field measurement of multiple antennas receiving or transmitting. 2. The ring-shaped reduced-pitch antenna test device according to claim 1, wherein the main reflection surface of the ring is composed of two orthogonal curves, and the trajectory of one curve is a circular line, the center of which is in the test quiet zone On a central axis of , the trajectory of the other curve is one of a parabola, a hyperbola, an ellipse, a circle, and a curve that can be represented by a formula. 3 . The ring-shaped reduced-pitch antenna test device according to claim 1 , wherein the main reflection surface of the ring is composed of two curves, a first curve is a circular curve, and the center of the circle is on the central axis of the test quiet zone. 4 . 4 . The ring-shaped reduced-pitch antenna test device according to claim 3 , wherein another second curve of the main reflection surface of the ring is a parabolic formula. 5 . 5 . The ring-shaped reduced-pitch antenna test device according to claim 3 , wherein another second curve of the main reflection surface of the ring is a hyperbolic formula. 6 . 6 . The ring-shaped reduced-pitch antenna test device according to claim 3 , wherein another second curve of the main reflection surface of the ring is an elliptic line formula. 7 . 7 . The test device for a looped telescopic antenna according to claim 3 , wherein another second curve of the main reflection surface of the loop is a curve that can be represented by a formula. 8 .

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